1. Field of Invention
Exemplary embodiments of the present invention relate to a method of manufacturing a substrate which is used for an electro-optical device such as a liquid crystal device and has a capacitor formed thereon, the substrate for the electro-optical device, and the electro-optical device and an electronic apparatus such as a liquid crystal projector provided with the same substrate. Exemplary embodiments of the present invention also relate to a method of manufacturing a substrate which is used for a general semiconductor device and has a capacitor formed thereon, and the substrate for the semiconductor device.
2. Description of Related Art
The related art includes a manufacturing method of a substrate for electro-optical devices. The method includes forming a capacitor on a substrate and having, a lower conductive layer, an intermediate layer which is a dielectric film, and an upper conductive layer sequentially deposited on the substrate. Next, by way of etching with one mask corresponding to a planar shape of the capacitor to be formed, the capacitor consisting of a lower electrode, a dielectric film and an upper electrode is typically obtained.
The related art also includes, a method of forming a capacitor on the substrate in which the upper electrode is smaller than the lower electrode or vice versa. In this case, by way of etching with a plurality of masks, the capacitor provided with the lower electrode and the upper electrode having a different shape from each other is formed.
However, in the method of preparing the lower electrode and the upper electrode having a different shape from each other, since a plurality of masks are used to pattern the lower electrode and the upper electrode to have a different planar shape, a manufacturing process becomes complicated and advanced. Generally, one mask is prepared by forming a resist on one surface and patterning the resist by way of photolithography or etching technique. Therefore, if a plurality of masks is used, it is necessary to repeat the above steps several times. Further, whenever one mask is used, a misalignment or dimensional variations may be generated, which results in a problem that poor manufacture may be caused. As a result, the production yield will be lowered naturally.
In addition, if the upper electrode and the lower electrode are manufactured so as to have a remarkably different shape, a region for the capacitor is increased, but a capacitance is lowered. The reason is that a region actually serving as the capacitor is limited to only a region in which the upper electrode and the lower electrode are opposed to each other with the dielectric film interposed therebetween. Further, though a difference in size between the upper electrode and the lower electrode is made smaller, there is a limit in forming a fine pattern since two large-sized masks are used. Therefore, it is difficult to obtain a capacitance corresponding to the formed area. That is, in preparing a capacitor in which the upper electrode and the lower electrode having a different planar shape are formed on a limited region of the substrate, there is a technical problem in that it is out of keeping with increasing the capacitance.
Alternatively, according to a method in which the upper electrode and the lower electrode are manufactured so as to have the same planar shape, it provides a relatively simple manufacturing process, but on ends of the dielectric film of the resultant capacitor, in order to increase the capacitance, edges of the upper electrode and edges of the lower electrode are opposed to each other via only an extremely thin dielectric film, respectively. For this reason, a slight misalignment or dimensional variations, film-forming foreign substance, film remnant or film-forming defects from an incomplete etching or removal may be caused, which results in a problem in that the edge of the upper electrode and the edge of the lower electrode may be electrically shorted from a concentration of electric field.